بررسی آزمایشگاهی عملکرد فرآیند الکتروفنتون در کاهش بار آلودگی فاضلاب کاستیک‌مستعمل پالایشگاه اصفهان

نوع مقاله: مقاله پژوهشی

نویسندگان

1 گروه مهندسی شیمی، دانشکده فنی و مهندسی، دانشگاه اصفهان، اصفهان، ایران واحد آب برق بخار، پالایشگاه نفت اصفهان، اصفهان، ایران

2 گروه مهندسی شیمی، دانشکده فنی و مهندسی، دانشگاه اصفهان، ایران

3 واحد آب برق بخار، پالایشگاه نفت اصفهان، ایران

چکیده

فاضلاب کاستیک مستعمل به دلیل قلیائیت بالا، حضور ترکیبات گوگردی، بار آلودگی بالا و زیست تخریب ناپذیری از مهم‌ترین چالش‌های زیست‌محیطی پالایشگاه‌ها به‌شمار می‌رود. در همین راستا، در این پژوهش مهم‌ترین عوامل فرآیندی تأثیرگذار بر بازده فرآیند اکسیداسیون پیشرفته الکتروفنتون شامل: پی اچ (در گستره 5-2)، نسبت هیدروژن پراکسید به میزان اکسیژن‌خواهی شیمیایی (75/0-2/0= H2O2/COD)، دما (C° 60-20)، زمان واکنش (min 135-45) و دانسیته جریان (mA/cm2 20-5)، به‌صورت هم‌زمان در کاهش بار آلودگی کاستیک مستعمل پالایشگاه نفت اصفهان به کمک طراحی آزمایش‌ها با روش سطح پاسخ (RSM) مورد بررسی قرار گرفت. نتایج تجربی نشان داد عوامل H2O2/COD، دما، پی اچ، دانسیته جریان و زمان واکنش به‌ترتیب بیشترین اثر را بر بازدهی واکنش داشتند. زمان‌ماند min 60، pH برابر 5/4، نسبت H2O2/COD برابر 6/0، دانسیته جریان mA/cm2 15 و دمای C° 60 به‌عنوان شرایط بهینه فرآیندی ارزیابی شد که بازدهی نهایی 96% را برای فرآیند الکتروفنتون برحسب شاخص COD در پی داشت. همچنین داده‌های تجربی نشان داد که با تغییر COD اولیه فاضلاب در محدوده (mg/L 60000 -12500) در شرایط بهینه، بازدهی کاهش بار آلودگی کاستیک مستعمل در گستره 94% تا 97% برحسب شاخص COD قرار داشت.
 

کلیدواژه‌ها


عنوان مقاله [English]

Treatment of Isfahan Refinery Spent Caustic by Electro-Fenton Process

نویسندگان [English]

  • kourosh Nasr Esfahany 1
  • Mehrdad Farhadian 2
  • Ali Reza Solaimany Nazar 2
  • Ghasem Ghafari 3
1 hemical Engineering Department, Faculty of Engineering, University of Isfahan, Iran/Environmental Research Institute, University of Isfahan, Iran
2 hemical Engineering Department, Faculty of Engineering, University of Isfahan, Iran
3 Isfahan Oil Refining Company, Isfahan, Iran
چکیده [English]

Spent caustic wastewater is one of the most important environmental challenges due to high alkalinity, the presence of sulfur compounds and non-biodegradable pollutants. Therefore, in this research, the effective parameters of Electro-Fenton process including pH range (2-5), H2O2/COD (0.2- 0.745), temperature (20-60 °C), reaction time (45- 135 min) and current density (5-20 mA/cm2) have been investigated on the COD removal efficiency by adopting response surface methodology (RSM). The results indicated that H2O2/COD, temperature, pH, current density and reaction time have the most effect on the pollutants removal, respectively. The optimum conditions have been found at pH =4.8, current density =14.8 mA/cm2, temperature =57 °C, reaction time =63 minutes and H2O2/COD =0.63 with 96% COD removal efficiency. According to the results, by changing of initial COD within 12,500 to 60,000 mg/L range at the optimum conditions, the pollutant removal efficiency has been increased from 94% to 97%.
 

کلیدواژه‌ها [English]

  • Spent Caustic
  • Electro-Fenton
  • AOP
  • Wastewater Treatment
  • Environment

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